US 12,077,657 B2
Olefin multi-block copolymer / silicone rubber compositions and foams formed from the same
Haiyang Yu, Shanghai (CN); Xiaolian Hu, Shanghai (CN); Hongyu Chen, Shanghai (CN); and Kyle G. Kummer, Lake Jackson, TX (US)
Assigned to Dow Global Technologies LLC, Midland, MI (US)
Appl. No. 16/958,727
Filed by Dow Global Technologies LLC, Midland, MI (US)
PCT Filed Dec. 28, 2017, PCT No. PCT/CN2017/119247
§ 371(c)(1), (2) Date Jun. 28, 2020,
PCT Pub. No. WO2019/127182, PCT Pub. Date Jul. 4, 2019.
Prior Publication US 2020/0332093 A1, Oct. 22, 2020
Int. Cl. C08L 23/00 (2006.01); C08J 9/00 (2006.01)
CPC C08L 23/00 (2013.01) [C08J 9/0061 (2013.01); C08J 2323/00 (2013.01); C08J 2483/04 (2013.01); C08L 2203/14 (2013.01)] 2 Claims
 
1. A foamed article formed from the composition comprising the following components:
A) from 80 to 90 wt % of an olefin multi-block copolymer, wherein the olefin multi-block copolymer is an ethylene/α-olefin multi-block copolymer having a density from 0.866 g/cc to 0.877 g/cc and a melt index (I2) from 0.5 to 1.0 g/10 min (190° C. and 2.16 kg);
B) from 10 to 20 wt % of a silicone rubber having a weight average molecular weight (Mw) ≥500,000 g/mole, a viscosity of equal to or more than 106 cSt at 25° C. and a total vinyl content ≥0.10 mole %, based on the weight of the silicone rubber, and as determined by 1H NMR, the silicone rubber comprising of structure iii):

OG Complex Work Unit Chemistry
where p is from 1 to 20, and q is from 2000 to 20000;
C) from 0.1 to 2 wt % of a crosslinking agent;
D) from 2.5-2.8 wt % of a blowing agent; and
E) from 0 to 5 wt % of one or more activators;
wherein the foamed article has a foam density from 0.25 to 0.30 g/cc, an abrasion DIN value of 140-190 mm3, Resilience of 69-70% and a wet COF value from 0.550 to 0.610.